BCM4718 chip pinout for adding second usb host

Many Netgear routers are using the BCM 4718 chips, like:
Netgear WNR3500 LV1, WNDR3300 v2, 3400 v1, 3700 v3, 4000, etc...

However, these routers has only 1 USB port, although their BCM4718 has two USB port

The ASUS RT-N16, Belkin F7d4301/8301 uses same BCM4718 chip and these routers have two USB port.

I think with some effort a second USB port can be added (as already done with an old  Linksys WRT54G)

All my search for the pinout for the BCM4718 did not find anything (the closest found was BCM4712)

Does anybody has info on BCM4718 pinout ?

Thanks!